1. Field of the Invention
The present invention relates to technology for displaying a three-dimensional image using a parallax barrier system.
2. Description of the Related Art
Conventionally, a parallax barrier system has been known as a method for achieving the display of three-dimensional images without using special glasses. A display apparatus using a parallax barrier system mainly comprises a display device that displays a left eye image and a right eye image by alternately aligning component images of the left eye and right eye images on every other vertical lines; and a parallax barrier that is placed in front of the display apparatus (the left eye image and the right eye image). The parallax barrier comprises a plurality of barrier regions that extend in a vertical direction of the left eye image and the right eye image and are aligned in the same pitch as the left eye image and the right eye image in a horizontal direction thereof; and a plurality of slit regions that are formed between the barrier regions. Further, in the parallax barrier system, a viewer views the display device through the parallax barrier away from a predetermined specific distance while viewing the left eye image only with his/her left eye and the right eye image only with his/her right eye, thereby recognizing a three-dimensional image; or, in other words, viewing a displayed image three-dimensionally.
WO 2007/024118A1 (Laid-open Japanese Patent Application No. 2009-506357), for example, discloses a display apparatus that has a parallax barrier constructed of a dot matrix type liquid crystal panel and controls a left eye image and a right eye image to be displayed on the display device as well as a pattern of the parallax barrier to be displayed (formed) on the liquid crystal panel. Specifically, the above-mentioned WO 2007/024118A1 discloses a display apparatus that, when the angle of the display device thereof is rotated 90 degrees, maintains a condition in which the left eye image and the right eye image are aligned in a horizontal (left-right) direction to the viewer's eye by displaying the left eye image and the right eye image that are rotated 90 degrees on the display device; and at the same time that maintains a condition in which a plurality of barrier regions are aligned in a horizontal (left-right) direction by displaying a parallax barrier in which a plurality of the barrier regions (slit regions) are aligned in a direction perpendicular to the direction prior to the rotation, that is, a parallax barrier possessing a different pattern. According to the display apparatus just described, it is possible to make the viewer recognize a three-dimensional image without any problem even when the display device changes its angle by rotating 90 degrees while a three-dimensional image is being displayed, for example.
However, in the above-mentioned display apparatus, it is necessary to control the patterns of the parallax barrier according to the angle of the display device displaying the image so that a plurality of the barrier regions (the slit regions) are always aligned in a left-right direction to the viewer's eye so that the viewer can recognize a three-dimensional image.